Artificial wool manufacturing process



Patented Mar. 24, 1936 2,3,Zli

ARTIFICIAL WOOL MANUFACTURING PROCESS Henri Chavassieu,

Izieux, France, assignor,

N Drawing.

No. 172,573. France April 3, 1926 19 Claims.

The present invention aims to produce a product of cellulose base which is an imitation of wool,- and to provide threads, filaments, etc., resembling wool.

More particularly, the invention seeks to produce viscose threads, filaments, etc. resembling wool by permanently incorporating in the viscose threads some of the constituents of wool, and specifically sulphur. A further object is to provide a means of permanently delustering viscose threads and filaments to resemble wool.

It has been proposed to produce artificial threads from cellulose resembling wool in appearance by mechanical or chemical deadening or roughening processes. These processes, however, seriously weaken the thread.

It has also been shown that when the ratio of carbon bisulphide to the alkali cellulose is much higher than the one commonly used, the thread resulting from the high carbon bisulphide viscose has a subdued luster. Under these conditions, however, spinning becomes extremely difiicult, due to the inadequate ripening of the viscose, and the resulting thread is below normal in strength.

According to my invention, sulphur is permanently incorporated into the cellulose thread. Due to the difierence in the refractive indices of sulphur and of cellulose, the thread, instead of having the marked luster of ordinary viscose threads, is dull and opaque. It resembles natural wool in its general appearance.

There is also an increase in the insulating power of the thread due to the presence of the sulphur. This is manifested by the feel of the yarn, which is more like wool than that of any other fiber. Resulting from my invention, I obtain threads, filaments, etc. which, after undergoing all the ordinary treatments, contain sulphur uniformly distributed throughout the mass, a fact which can be ascertained by microscopical inspection. From said treatments, however, should be excepted those in which an ordinary or concentrated alkali solution is used, for such treatments have indeed a destructive effect on natural wool itself.

There are, of course, many ways in which I can permanently incorporate the sulphur into the cellulose threads.

I can prepare viscose threads in the normal manner, using the customary viscose and coagulating bath, and then treat the resulting threads either in their freshly coagulated condition or after washing and drying. In these cases, the threads are treated with a solution of alkali salts rich in sulphur, to which has been previously Application March 3, 1927, Serial Renewed August 4, 1931.

added caustic soda or some other material capable of swelling the thread. The so-treated thread is subsequently subjected to' an acid bath adapted to liberate the sulphur from the first bath and so precipitate the sulphur onto the threads.

The sulphur may be introduced into the viscose by the addition of materials which, at the time of spinning, will precipitate sulphur in the filaments in a finely dispersed condition.

Normal viscose, such as is commonly used for solid or hollow threads, may also be used and coagulated in a spinning bath containing sulphur in a very finely dispersed condition. It is obvious that sulphur itself may be added to the bath, or that sulphur compounds which liberate sulphur by reaction with the bath may be used.

In order to clearly show my invention and methods of carrying my invention into practice, I shall present below examples giving the precise details of the methods involved. It clearly understood, however, that these examples are given by way of illustration only, and that the invention is not to be so limited except as set forth in the appended claims.

When normal viscose is used and is spun into a coagulating bath containing the sulphur, one of two methods may be used. Either a salt which is rich in sulphur and which will produce sulphur by reaction with the coagulating bath acids, is introduced into the bath, or colloidal sulphur itself is introduced into the bath.

Example 1.As an example of the method by which the sulphur is added to the spinning bath, I may use a spinning bath containing the usual percentages of acids and salts, and add to it from to 20 grams per liter of starch and from 50 to 70 grams per liter of commercial sodium hyposulphite. It is even more satisfactory sometimes to add a mixture of sodium hyposulphite and sodium sulphide in the proportions resulting from the following formula:

That is to say, about one part of anhydrous sodium hyposulphite to two parts of sodium sulphide, calculations being made for the actual strength of the commercial products which are used. This mixture is acidified by sulphuric acid.

Example 2.As an example of the method in which the sulphur is added to the viscose, I may add to the caustic soda which is to be used for dissolving the cellulose xanthate quantities of sodium hyposulphite and sodium sulphide, corresponding to about 8 parts of sulphur for each 100 parts of cellulose. The sulphur contained in these should be additions will be uniformly dispersed and fixed in the cellulose when the viscose containing the salts reacts with the coagulating bath during spinning.

Example 3.-As an example of the method in which the threads themselves are treated with sulphur, I may immerse a celulosic textile thread, whether artificial or natural, and whether in the state of continuous or discontinuous filaments, into a solution which contains per liter 25 to '75 grams of caustic soda, to 150 grams of sodium sulphide, and 120 to 200 grams of sodium hyposulphite. This bath is maintained at ordinary temperature. At the end of about 15 minutes the threads are removed from the bath and allowed to drip. They are then placed in or passed through a mildly warm bath containing about to 200 grams of sulphuric acid monohydrate per liter. They are subsequently washed with hot water, centrifuged, and dried without tens1on.

This method is especially suitable for filaments dried without tension, their dullness or deadness being increased thereby.

Filaments and threads obtained by any one of the foregoing methods have a sulphur content varying from 2 to 5 per cent. These treated threads and filaments become even more closely similar to wool if, in the foregoing examples, I use, instead of ordinary viscose, a solution of cellulose xanthate in caustic soda to which has been added, in addition, certain albuminoids such as are described in my French Patent 395,402. The effect of these added albuminoids is to produce cellulosic threads having the same dyeing afiinities as natural wool.

Similarly, if it is especially desirous to produce threads of a cellulosic base closely approximating wool in their slightly rough feel, I may introduce into the above-mentioned viscose a silicate, an aluminate, a resinate, or any other body adapted to become fixed in the coagulated thread so as to decrease the smoothness of the finished material.

The effect obtained through the various methods which have been enumerated above can also be increased by leading the thread as it emerges from the spinning bath into a colloidal solution of sulphur, and then into a bath capable of precipitating the sulphur which has been absorbed.

Should a hollow-filament thread be desired, I wish it to be clearly understood that all that will be required is to use a viscose forming an emulsion with air or with any inert gas, or a viscose containing air or any neutral gas in solution, or even a viscose containing a material calculated to develop, under thermic or chemical action, gaseous bubbles within the cellulose filaments at the time of spinning.

Whether solid or hollow, any filaments obtained through the process which is the subject matter of my invention can be bleached without having to be previously desulphured.

Having now particularly ascertained and described the nature of my invention, and as well the manner in which it is performed, I declare that what I claim is:

1. In a process of manufacturing cellulosic threads, filaments and the like, resembling natural wool in appearance, feel and insulating power, the step of introducing into the interior of viscose threads a quantity of sulphur at least equal to the sulphur content of natural wool.

2. In a process of delustering viscose threads,

filaments and the like, the step of introducing into the interior of the threads finely-dispersed sulphur in amounts at least equal to that present in natural wool.

3. In a process of delustering viscose threads, 5 filaments and the like, the step of introducing into the viscose from which the threads are to be formed a body which will produce sulphur, such sulphur becoming fixed in the interior of the threads during the spinning operation.

4. In a process of delustering viscose threads, filaments and the like, the step of introducing sodium hyposulphite into the viscose.

5. In a process of delustering viscose threads, filaments and the like, the step of introducing a mixture of sodium hyposulphite and sodium sulphide into the viscose.

6. In a process of delustering viscose threads, filaments and the like, the step of introducing a mixture of sodium hyposulphite and sodium sulphide corresponding to about 8 parts of sulphur for every 100 parts of cellulose into the viscose.

'7. An artificial textile product resembling natural wool in appearance, feel and insulating power, comprising coagulated viscose threads containing in their interior a quantity of sulphur in a finely dispersed state at least equal to the sulphur content of natural wool.

8. A process of producing delustered artificial threads, filaments and the like formed from viscose comprising introducing sodium hyposulphite into the viscose and spinning said solution, whereby the sulphur is precipitated in the thread.

9. A process of producing delustered artificial threads, filaments and the like formed from viscose comprising introducing a mixture of sodium hyposulphite and sodium sulphide into the viscose and spinning said solution in an acid bath.

10. A process of producing delustered artificial threads, filaments and the like formed from viscose comprising introducing a mixture of sodium hyposulphite and sodium sulphide corresponding to about 8 parts of sulphur for every 100 parts of cellulose into the viscose and spinning said viscose in an acid bath.

11. In a process of producing artificial textile threads or filaments resembling natural wool in appearance, feel and insulating power, the steps of introducing a mixture of sodium hyposulphite and sodium sulphide into the viscose and adding an albuminoid thereto.

12. In a method of producing artificial textile threads or filaments resembling natural wool in appearance, feel and insulating power, the steps of introducing a mixture of sodium hyposulphite and sodium sulphide into the viscose and adding a material which becomes fixed in the thread or filament and decreases the smoothness of the finished thread.

13. An artificial delustered thread or filament containing approximately 2%-5% of sulphur.

14. An artificial delustered thread or filament containing approximately 2%-5% of sulphur uniformly distributed therein.

15. A process of producing artificial filaments and the like formed from viscose, comprising introducing sodium hyposulphite into the viscose and spinning said solution into an acid bath, 70 whereby sulphur is precipitated in the thread.

16. A process of producing thread resembling wool which comprises spinning a viscose solution in a coagulating bath containing sodium hyposulphite and sodium sulphide.

17. A process of producing thread resembling wool which comprises spinning a viscose solution in a coagulating bath containing sodium hyposulphite and sodium sulphide in the proportion of one part of the former to two parts of the latter.

18. A method of producing thread resembling wool which comprises immersing a cellulose textile thread in a solution containing caustic soda,

sodium sulphide and sodium hyposulphite, re-

moving the thread and then treating it with an acid.

19. A method of producing thread resembling wool which comprises immersing a cellulose textile thread in a solution containing per liter to grams of caustic soda, to 150 grams of sodium sulphide, to 200 grams of sodium hyposulphite, removing the thread and immersing it in an acid bath.

HENRI CHAVASSIEU. 

